This application claims the benefit of Belgian Application No. 2004/0536 filed Nov. 4, 2004, which is hereby incorporated by reference in its entirety.
The invention relates, first of all, to a method for weaving fabrics on a weaving machine, wherein in successive weft insertion cycles two weft yarns are simultaneously inserted at a different weft insertion level between pile warp yarns which are positioned by means of a three-position-non-open-shed Jacquard machine, wherein this Jacquard machine is provided to maintain one or several pile warp yarns in successive operating cycles of the weaving machine in an upper and/or lower position.
Secondly, the invention relates to a three-position-non-open-shed Jacquard machine, wherein the Jacquard machine is provided for positioning pile warp yarns such that two weft yarns are simultaneously inserted at a different weft insertion level between the said pile warp yarns by means of a weaving machine in successive weft insertion cycles, and wherein the Jacquard machine is provided to maintain one or several pile warp yarns in successive operation cycles of the weaving machine in an upper and/or a lower position.
Thirdly, the invention relates to a Jacquard weaving machine, more specifically a face-to-face double-rapier weaving machine, which is provided to carry out a method according to the invention.
Lastly, the invention relates to a method to rearrange the harness suspension of a three-position-non-open shed Jacquard machine, wherein the harness suspension is provided with heddles for positioning pile warp yarns of one or several frames, wherein two weft yarns are simultaneously inserted between the said pile warp yarns at a different weft insertion level by a weaving machine in successive weft insertion cycles, and which is provided to maintain the pile warp yarns of one or several frames in successive operating cycles of a weaving machine in an upper and/or a lower position.
There is a strong tendency to realize fabrics having different structures within the same fabric.
In patent application EP 1 347 087 a method and a device are described to manufacture fabrics using face-to-face weaving techniques comprising a large variety of structures. Thus an almost infinite number of combinations is possible of cut pile with loops and with warp yarns forming patterns which are interlaced across one or several weft yarns, so-called flat weave or likewise called fabrics with floating pile across several weft yarns. In order to produce such fabrics especially adapted machines are required: three-rapier weaving machines equipped with two rows of spacers which have to meet certain specific requirements as to form, and the machine should likewise be equipped with a universal (open shed) 4-position Jacquard machine.
Such machines provide quite some possibilities, but they have the disadvantage that most of the time they will require a specific investment in new machines.
Fabrics having no zones with a loop pile, but containing zones with flat weave, also present large possibilities to provide structural variations in a pile fabric.
In patent application EP 0 459 582, a double-rapier weaving machine with a non-open-shed Jacquard machine is described, allowing fabrics to be produced with cut pile and with zones with flat weave woven in a ½V-weave. In doing so, however, pattern forming of the flat weave should be restricted to pattern forming warp yarns to be situated every two weft yarns only on the pile face. Here, floating pile running across several weft yarns is not possible, because the non-open-shed Jacquard machine, as known from the state-of-the-art does not allow for movements, in which it is possible to maintain the central position between the two rapiers during two successive weft insertion cycles.
Therefore, a universal (open-shed) three-position Jacquard machine is required. This machine, however, will have the inherent disadvantage that per outgoing harness cord and therefore per pile warp yarn to be controlled, two actuators (for instance solenoids) will be required. Jacquard machines having two solenoids per outgoing harness cord are expensive and therefore they are not so readily available on the market.
By means of a non-open-shed-three-position Jacquard machine, fabrics may be woven however on a double rapier weaving machine presenting a combination of cut pile and zones with flat weave, wherein in the zones with flat weave the pattern forming warp yarn is floating across several weft yarns, this when by means of weft cancellation or weft disengaging at each insertion only one weft is inserted in the so-called 1/1V-weave.
The disadvantage of this method is that it is less productive, as per weft insertion cycle of the machine only one weft is applied in a useful manner.
The purpose of the invention is to provide a method and a device for weaving fabrics on a weaving machine having two weft insertion levels and which is equipped with a three-position-non-open-shed Jacquard machine, wherein one or several zones with floating pile across several weft yarns may be woven.